Feed control for machine tools



April 1944- E. P. BULLARD, 30., ETAL ,346,660

FEED CONTROL FOR MACHINE TOOLS Filed Oct. 31, 1939 5 Sheets-Sheet l ATTORN April 18, 1944. E. P. BULLARD, 30., ET AL ,346,660

FEED CONTROL FOR MACHINE TOOLS Filed Oct. 31, 1939 5 Sheets-Sheet 2 I Q o my [37 :f: 34 a Q /38 l 1! 33 I07 32 I08 :3; J/ 28 lffa F- 2 a:

| ml l f1 I Z l 7 3 /30 j 27 I E mv w April 18, 1944.

E. P. BULLARD, 30., ETAL 2,346,660

FEED CONTROL FOR MACHINE TOOLS Filed Oct. 31, 1959 5 Sheets-Sheet 3 (A; v m W.

April 1944- a P. BULLARD, 30., ETAL 2,346,660

FEED CONTROL FOR MACHINE TOOLS Filed Oct. 31, 1939 5 Sheets-Sheet 4 R YE mumm H Nu N W N o NP H I h emu A RH w MLUMIQ/ I f Y B M April 18, 1944. p, BULLARD, 3 E 2,346,660

FEED CONTROL FOR MACHINE TOOLS Filed Oct. 51, 1959 5 Sheets-Shet 5 FEED CONTROL FOR MACHINE TOOLS Edward P. Bollard, III, Fair-field, and Leroy E.

Alvey and Paul H. Lange, Bridgeport, Coma, assignors to The Billiard Company, a corporation of Connecticut Application October 31, 1939, Serial No. 302,196

24 Claims.

This invention relates to transmissions for moving a member along one or more paths, and particularly to apparatus for disengaging the member from the transmission at 'pre-selected points along its paths of movement.

The broad principles of the invention may be applied to any apparatus in which an element is adapted to be moved from one position, where certain forces act to perform a function, to an inactive position, or through an inactive position to another position, where certain other forces act to perform another function.

Objects of the invention include, the provision of apparatus capable of amplifying a relatively slight rectilinear movement and transmitting the amplified movement to a remote point within substantially a minimum time interval; the provision of apparatus in which a member is adapted to be shifted from one axial position to another axial position by an oscillatable element and to be centralized between said axial positions by a reciprocable member cooperating with an oscillatable element; the provision of apparatus including a movable member in which the travel of the member is substantially instantaneously stopped at preselected points by the action of a reciprocable member cooperating with an oscillatable member; the provision of apparatus in which a member is adapted to be moved along intersecting paths by separate driven shafts, and stopped at preselected points in either of its paths by the cooperation of a single reciprocable member that cooperates with oscillatable means associated with each of the driven shafts; the provision of apparatus including an indexable turret head adapted to be moved along a rectilinear path and provided with a device for selectively engaging adjustable abutments for each station of said head for imparting slight rectilinear movement to a member on which said abutments are mounted when the head is moved along its rectilinear path; the provision of such apparatus including a turret "head having safety features to prevent breaking or overloading the device that selectively engages the adjustable abutments; and the provision of apparatus including a transmission in which a movable member is provided with a selectively operable arm adapted to engage an abutment adjustably mounted on a reciprocable member, the movement of which operates the starting switch of a fluid-operated thrustor to disengage the member from the transmission of the apparatus.

Other objects and novel features of the invention will become apparent from a consideration of the following specification and accompanying drawings in which:

Fig. 1 is a front elevational view of a portion of a vertical turret lathe to which the principles of this invention have been applied;

Fig. 2 is a right-hand side elevational view of the apparatus shown in Fig. 1, certain parts being removed, and certain other parts broken away to show constructional features of the apparatus;

Fig. 3 is a sectional view taken substantially along line 3-3 of Fig. 2:

, Fig. 4 is a top plan view of the transmission housing with a portion of the cover removed;

Fig. 5 is a front elevational view of the apparatus shown in Fig. 4, with parts broken away to disclose sectional views of certain features of the invention as viewed substantially along line 5-5 of Fig. 4;

Fig. 6 is an enlarged sectional elevational view taken substantially along line 8-6 of Fig. 1; and

Fig. 7 is an enlarged sectional view taken sub stantially along line 1-! of Fig. 1.

Referring to the drawings, a turret head H is mounted on the front of a standard S and is adapted to be moved along intersecting paths under the influence of a feed-works transmission F. The feed-works F is driven by means (not shown), which delivers a plurality of relatively slow speeds of rotation, and a substantially constant, relatively fast speed of rotation to each of a pair of driven shafts that control the move ment of the head H along its intersecting paths. During operation of the machine it is necessary to limit the travel of the head H within extremely close limits by disengaging it from the feed-works F at various preselected points along the path of travel of the head. Accordingly, a feed knock-out mechanism K is provided between theturret head H and the feed-works F (Figs. 1, 2 and 5). The operation of the feed knock-out K is initiated by a relatively slight movement of the head H after it has arrived at a preselected position along either of its paths of travel. This slight movement actuates a switch to energize the circuit of a motor for starting the pump of a 'iluid-operated thruster. The thrustor instantly ably mounted on a pin fixed to the lower end of a turret slide 28. The slide member 28 is constructed with longitudinal bearing grooves which cooperate with mating guide bearings 28 on a swivel 38 which latter is provided with a connector adapted to ride in an arcuate groove 3| located in the front face of a saddle 32 (Fig. 2). The saddle 32 is provided with an arcuate rack 33 which cooperates with a worm gear on a shaft 34 journaled in the swivel 38. The saddle 32 is supported on a horizontally disposed slide bearing 35 of a cross-rail 38, which latter is gibbed to the with corresponding clutch surfaces on the faces I of gears 69 and 18 that face each other. Power from splined shaft 62 is transmitted through suitable gearing to the gears 68 and 18 so that these gears rotate in opposite direction at substantially a constant, relatively rapid speed. Selective shifting of the clutches 68 and H will cause shaft 65 to be driven in opposite directions at a plurality of separate relatively slow speeds, and at a substantially constant, relatively rapid speed.

, The rotation of shaft 65 is transmitted to the front face of the standard S and is adapted to be moved vertically therealong by the rotation 'of vertically disposed screws 31 located on eachside of the standard S. r

The head H is moved horizontally along the slide bearing of the cross-rail 36 by a horizontally disposed screw 38 (Figs. 1 and 2) that is threaded into a boss 39 on the rear of the saddle 32. Reciprocation of the turret H along bearings 29 of swivel 38 is effected by a splined shaft 48 (Fig. 3) parallel with screw 38 that slidingly supports a bevel gear 4| that meshes with a bevel ear 42 fixed to one end of a stubshaft 43. The stub shaft 43 is journaled in the saddle 32 and the swivel 38 at the center of the arcuate groove 3|, thereby providing a pivot for the swivel 38. The end of the stub shaft 43 opposite to that which supports gear 42 fixedly supports a bevel gear 44 in mesh with a bevel gear 45 (Fig. 2) keyed to a vertically-disposed screw 46, the upper end of which is threaded into a boss 41 fixed to the top of the slide member 28, and the lower end of which is journaled in a bearing near the bottom portion of the swivel 38. From the foregoing it is apparent that rotation of the horizontal screw 38 and the splined shaft 48 will effect movement of the turret head H horizontally along the crossrail .38, and along the bearings 29 of swivel 38 respectively.

l'totative power for screw 38 and shaft 48 is provided by the feed-works F rigidly mounted on one endof the cross-rail 36. i

The feed-works F forms no part of the present invention, and it will be described only generally to: illustrate the. principles of the present invention. The feed-works F is fully described and claimediin co-pending application, Serial No.

299,134, filed Oct. 12,1939, inthe name'of Edward.

P.'Bullard-,=1II.

--Power is adapted to. be supplied to the feedworks transmission F by rotating shafts 62 and 63 by-any suitable'means not shown. The shaft 62 is adaptedto be rotated at a relatively rapid constant speed and the shaft 63 is adapted to be rotated at a relatively slow speed.

Referring to Fig.4, the feed-works includes a driving shaft65 on which apair of gears 66 and 61 are journaled. 'Apositive-action clutch 68 is splined to shaft 65 and is provided with clutch teeth on each of its faces adapted to mesh with corresponding clutch teeth on the sides of gears 66 and 61 that face each other. The gears 66 and 61 are adapted to be rotated in opposite directions the clutch 68.

splined shaft 48 through a pair of bevel gears 12,

' moved from one axial position, where the shaft 65 is rotated either at a plurality of relatively slow speeds or at a substantially constant, relatively rapid speed in a forward direction, through an inactive or neutral position, to another axial position where the shaft 66 is rotated in a reverse direction under the same circumstances as it was rotated in the forward direction. The axial shifting of the clutches 68 and II is effected by the oscillation of a' pair of axially-aligned oscillatable sleeves l4 and 15. The sleeve 14 is provided with a circumferential groove 16 that cooperates with a roller mounted on an arm 11 connected to a yoke element 11' in engagement with Likewise, the sleeve 15 is provided with a circumferential groove 18 that cooperates with a roller mounted on an arm 19 connected to a yoke 18 in engagement with the clutch I I.

lective oscillatable movement of the sleeves 14 and I5 is provided by a relatively long shaft 88 extending therethrough. The shaft 88 is provided with pins 8| and 82 that are adapted to be moved into and out of engagement with slots 83 and 84 in the non-adjacent ends of the sleeves l4 and 15. The shaft 88 extends to the outside of thefeedworks F and is provided with a handle 85. Axial shifting of the shaft 88 to the left as viewed in Fig. 4 causes pin 8| to engage slot 83, whereupon oscillating shaft 88 effects shifting of the clutch- H into and out of engagement with either gear 66 or 18 to thereby drive shaft 65 at a substantially constant relatively rapid speed in either direction. Axial shifting of the shaft 88 to the right as viewed in Fig. 4, will cause pin 82 to engage slot 84, whereupon oscillating shaft 88 will effect shifting of clutch 68 into and out of engage ment with either gear 66 or 61 to drive shaft 65 at a plurality of relatively slow speeds in either direction. The shaft 88 is adapted to extend through an opening in a cup-shaped member 88'.

" The opening includes a slot 8| through which the pin 8| is adapted to pass only when the shaft 88 is in position insuring the neutrality of clutches 68 and II This construction, therefore, prevents the shifting of the clutches 68 and 'H into effective position at the same time. 7

Referring to Fig. 5, a shaft 86 identical with, and located directly beneath shaft 65 is adapted to support four gears for driving screw.38 in both directions at a plurality of relatively slow speeds, and at a substantially constant relatively rapid speed in the same manner that shaft 65 drives splined shaft 48. Likewise a shaft 81 identical with shaft 88 is provided for selectively oscillating an additional pair of axially-aligned sleeves for controlling the shifting of clutches on the shaft 86 in the same manner that shaft 88 is adapted to selectively oscillate the axially-aligned sleeves l4 and 1,5 that shiftthe clutches 68 and H on shaft 65. The specific construction of the feedworks for effecting these functions is more fully described in the above-referred-to co-pending application, Serial No. 299,134.

From an inspection of Figs. 4 and 5, it is apparent that the clutches 68 and H on shaft 65 and the corresponding clutches on shaft are adapted to be moved from one axial position through neutral to another axial position in order to engage the various gear combinations within the feed-works F with the screw 38 and shaft 40. Furthermore the axial shifting of these clutches is effected by the oscillation of shafts 80 and 81 an equal amount on either side of central neutral positions.

The feed knock-out K is adapted to return the oscillaltable shafts 80 and 81 to their central positions, thereby neutralizing the clutches 68 and TI on shaft '85 and the corresponding clutches on s'haft 86. This function is adapted to occur when the head H arrives at a predetermined point in either of its intersecting paths.

Referring to Fig. 5, the feed knock-out mechanism K includes collars 9| and 92 clamped to shafts 80 and 81 respectively. The collar 9| is provided with two ears 93 that are disposed on opposite sides of, and hav surfaces that lie in, a plane that intersects shaft 80. Collar 92 is identical with collar BI and it is clamped on shaft 81in the same manner as collar9 I is clamped on shaft 90. The cars 93 on both collars 9| and 92 are adapted to lie in substantially horizontal planes when the shafts 80 and 81 and their corresponding clutch elements are in neutral. Oscillating shafts 80 and 81 to shift their corresponding clutches into driving position, causes the planes that contain ears 93 to become angularly disposed with respect to the horizontal as illustrated by the dotted lines in-Fig. 5. A vertically-disposed shaft 94 adjacent the shafts 80 and 81 is provided with a relatively long ver tically-reciprocable sleeve 95. The sleeve 95 rigidly supports yoke elements 95 and 91 that overlie the ears 93 of collars 9| and 92 on shafts 80 and 81. Normally, the sleeve 95 is urged upwardly out of active position by a spring 98. Movement of the sleeve 95 downwardly causes the legs of yokes 96 and 91 to engage the ears 93 forcing the collars 9| and 92 into a position where the ears lie in substantially horizontal planes, thereby insuring that the clutches controlled by the shafts 80 and 81 are in their neutral positions.

Referring to Figs. 4 and 5, vertically-downward movement of the sleeve 95 is effected by the actuation of a fiuid-operated electrically-controlled thrustor 99; back of the feed-works F and is of conventional design, comprising a cylinder in which a vertically-reciproc'able plunger is adapted to operate. The plunger is provided with a rod I00 pivotally connected to a link I 0| that extends forward- 1y to near the front of the feed-works. Referring to Fig.4, the link IOI is rigidly connected to a shaft I02 that extends transversely through the feed-works and on which the yoke element 11' is journaled. A pusher link I03 is rigidly connected to the shaft I02 and includes an abutmerit portion I04 that overlies a portion of one of the yokes 96 or 91. Accordingly, energization of the circuit of a motor that operates the thrustor 99 causes an upward movement of the rod I00 and link IOI, thereby turning shaft I02 so that link I03 is forced downwardly into engagement with oneof the yokes 96 or 91 and causing their downward movement which will oscillate either of shafts 80 and 81 into their neutralpositions if The thruster 99 is located on the they are not already n such position. Accordingly such action will disenga e the feed-works F from the shafts 38 and 40 thereby stopping the head H at preselected points along it respective paths.

Referring to Figs. 1, 2., and 3, energization of the circuit of the motor for the thrustor 99 is effected by a relatively slight rectilinear move ment of a plate I 05 mounted for reciprocation in slide bearings I08 (Fig. 3) on the swivel 30. This relatively slight rectilinear movement of the plate I05 is adapted to actuate an arm I01 (Fig. 1) of an electric contact I08likewis mounted on the swivel 30. Referring to Fig. 6, the mounting of plate I05 on the swivel 30 includes an eye bolt I09 fixed to the top of plat I05 for rigidly supporting a shaft I extending downwardly into a bored opening III in the swivel 30. The bore III is counterbored at 2, H3 and a gland H0, fixed in counterbored portion H2, forms a slide bearing for the shaft H0. A'pair of collars H5 surround a portion of the shaft ill] and are mounted for free rotation and sliding movement thereon. The lower collar II5 abuts against the bottom of the counterbored portion H3 while the upper collar II5 bears against the lower end of the gland II4. A compression spring H8 surrounds the lower end of the shaft Ill) and is located between the collars H5. The construction issu'c h that the reciprocable plate I05 is resiliently urged towards a central position upon the release of a force that has moved it to either side of said central position.

Referring to Fig. 1, plate I05 is provided with a cam II1 having high portions on each side of alow portion H8. The spring H6 (Fig. 6) nor mally locates the plate I05 in a position where a roller on arm I01 of switch I08 is resiliently urged into the low portion H8 of cam H1 normally holding the switch I08 open. Upon relatively slight rectilinear movement of plate I05 in either direction the arm I01 of switch I08 will be turned in a clockwise direction thereby closing the switch I08, energizing the circuit of the motor for the thrustor I09, and causin the feed-works F to become disengaged from the screw 38 and shaft 99.

In the present embodiment of the invention the turret head H consists of five stations. It is desirable to provide a control between each of the specific stations of the turret head H and the electric switch I08 so that automatic operation of the machine may be effected. Referring to Figs. 1 and 3, the plate I09 is provided with five parallel grooves H9 adapted to receive abutment members I20 at both ends thereof. The abutment members I20 are adapted to be adjustabiy located along their grooves to control the stroke of the turret head H. A reciprocable arm it! provided with a finger portion I22 is adapted to be selectively moved across the grooves its into position aligned with the abutments iZil. Controlof the reciprocation of the arm I2I is effected by the indexing of the turret head H. A cam groove I23 (Fig. l) is provided on the back face of the turret head H-adapted to receive a rolicr I 20 mounted on the lower end of a reciprocable rod 025. The rod I25 is provided with a rack I26 at its upper end adapted to mesh with a gear 121 (Fig. 3) of a gear unit I28. The gear unit I28 is journ'aled on a stub shaft I29 and includes an additional gear I30 adapted to mesh with rack teeth I8I formed on the arm I2I. The construction of the cam groove I29 is designed to cause reciprocation of the rod I25 to successively move the finger I22 of the rod I2I into aligned relation with the abutments I20 within the various grooves II9. In this manner, as the head H is indexed, the finger I 22 automatically moves into alignment with the abutment I20 within the groove II9 corresponding to the station of the turret head. that is in working position.

Several safety features are provided to prevent breakage of the parts in the event the operator inadvertently leaves an abutment I20 in position such that the finger I22 will engage its side as it moves across the plate I05, and in event that the finger I22 encounters an excessive load when it engages an abutment I20 as it moves in either direction with the head H. Referring to Fig. 3, finger I22 is pivotally mounted on a pin I32 extending across a bifurcated end portion of the rod I2I. A spring-pressed detent I33 is adapted to cooperate with a notch in the ide of the finger I 22 to retain it against oscillatable movement about the pin I32. The finger I22 is,

therefore, mounted so that relative movement between it and the arm I2I may be accomplished in one direction but not 11 the other. Accordingly, should the finger 22 engage the side of an abutment I20 while moving across the plate I05, it will merely pivot around the pin I32 and prevent breakage thereof. Manual re-setting of the finger I22 is necessary before it can be employed to reciprocate the plate I05.

The rack teeth I3I on the arm I2I extend peripherally about the arm I2I and form another safety feature. A longitudinally-extending groove I34 is provided in the rod I2I into which a spring-pressed detent I35 (Fig. 7) is adapted to seat and to releasably retain the arm I2I against rotation. However, should the reciprocation of plate I require an excessive force, such that the finger' I22 might be broken, the arm I2I will merely rotate about its longitudinal axis. Manual re-setting of'the arm I2I can be effected by applying a wrench to the squared end I30 (Fig.1) of the arm I2I.

Referring to Fig. 6, an angle member I3I is mounted at the top of the plate I05, to which a rod I38 is fixed in aligned relation with the arm I2I. The construction and arrangement is such that if the finger I22 fails to engage an abutment I20, the upward travel of the turret or main head H would be limited by the engagement of arm I2I with rod I38 causing the plate I05 to be raised thereby closing the contact I08 to energize the motor circuit for the thrustor 99.

Although the various features of the improved feed knock-out mechanism have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that numerous changes may be made in such details, and certain features may be used without others, without departing from the principles of the invention. Furthermore, although the principles of the invention have been shown and described in connection with the movement of the main or turret head along the bearings 23 in the swivel 30, they can be applied with equal facility to the movement of said main head along the cross-rail 36 by mounting a plate on the crossrail similar to plate I05 and employing a switch similar to switch I08 that could be wired in parallel with the circuit of switch I08.

What is claimed is:

1. Apparatus comprising a clutch adapted to be shifted from one axial position to another axial position; a yoke connected to said clutch having an arm supporting a roller; an oscillatable sleeve having a peripheral cam groove adapted to receive said roller; abutments located on oppositesides of means adapted tocooperate with said sleeve; a reciprocable member having means adapted to cooperate with said abutments to move said sleeve to position said clutch substantially midway between said axial positions; and a fluid operated thrustor adapted to move said reciprocable member.

2. Apparatus comprising a plurality of members adapted selectively to be shifted between two axial positions; separate oscillatable means for shifting said members between saidaxial positions; common oscillatable means adapted to be selectively engaged to anddisengaged from said separate oscillatable means; means for preventing disengagement of said common means from either of said separate oscillatable means until the latter is in position to locate its corresponding member substantially midway between its axial positions; and a reciprocable member adapted to co-operate with means on said common means for positioning the member in engagement with said common means substantially midway between its axial positions.

3. Apparatus as claimed in claim 2, in which said separate oscillatable means comprises a pair of axially-aligned sleeves having peripheral cam grooves; and said members are provided with arms supporting rollers adapted to co-operate with said cam grooves.

4. Apparatus as claimed in claim 2, in which said separate oscillatable means comprises a pair of axially-aligned sleeves having peripheral cam grooves; said members are provided with arms supporting rollers that co-operate with said cam grooves; and said common oscillatable means comprises an axially-shiftable shaft extending through said axially-aligned sleeves and provided with means for engaging one of said sleeves in each of its axially-shiftable positions.

5. Apparatus as claimed in'claim 2, in which said separate oscillatable means comprises a pair of axially-aligned sleeves having peripheral cam grooves; said members are providedwith arms supporting rollers that co-operate with said cam grooves; said common oscillatable meanscomprises an axially-shiftable shaft extending through said axially-aligned sleeves and includes means for engaging oneof said sleeves in each of its axially-shiftable positions; and said means for preventing disengagement of said axiallyshiftable shaft from eith'er of said sleeves comprises a cup-shaped member through which one end of said shaft passes, said cup-shaped member additionally includes a slot through which the means for engaging one of said sleeves is adapted to pass, said slot being arranged so that the sleeves must be in position where their corresponding axially-shiftable members are substantially midway between their axial positions before said shaft can be axially shifted to disengage one sleeve and engage the other.

6. Apparatus comprising two pairs of members each member being adapted to be shifted between two axial positions; each pair of said members being arranged on parallel spaced shafts;

separate oscillatable means for shifting each of means common to each pair of said oscillatable means adapted to be selectively engaged to and operate with means on both of said common means for positioning the members substantially midway of their axial positions.

7. Apparatus as claimed in claim 6, in which means is provided for preventing the disengagement of either of said common means from either of the oscillatable means of the pair said common means controls until the oscillatable means with which said common means is engaged is in position to locate its corresponding member substantially midway between its axial positions.

8. A transmission for moving an element comprising in combination, a driving shaft, a driven shaft; gearing for transmitting power from said driving shaft to said driven shaft, including means for rotating said driven shaft in opposite directions; a clutch for selectively engaging said.

driven shaft with said oppositely rotatable means; oscillatable means for shifting said clutch from one axial position through a neutral position to another axial position; neutralizing means independently movable relatively to said oscillatable means, adapted to co-operate with said oscillat able means for shifting said clutch to its neutral position; and power-operated means responsive to the movement of said element for actuating said neutralizing means substantially instantaneously.

9. A transmission as claimed in claim 8, in which said clutch-neutralizing means comprises a reciprocable member.

10. A transmission as claimed in claim 8, in

. which said oscillatable means is. adapted to be moved in opposite directions from a neutral position; and said clutch-neutralizing means comprises a reciprocable member adapted to return said oscillatable means to its neutral position.

11. A transmission comprising in combination, a driving shaft; a driven shaft; gearing for transmitting power from said driving shaft to said driven shaft including means for rotating said driven shaft in opposite directions at a plurality of relatively slow separate speeds, and at a substantially-constant relative fast speed; a pair of clutches for selectively engaging said driven shaft with any one of said oppositely-rotatable means; separate oscillatable means for shifting said clutches from one axial position through a neutral position to another axial position; common oscillatable means adapted to be selectively engaged to, and disengaged from said separate oscillatable means; means for preventing disengagement of said common means from either of said separate oscillatable means until the latter is in position to locate its corresponding clutch in neutral; and a reciprocable member adapted to co-operate with means on said common means for shifting the clutch in engagement with said common means into neutral.

12. A transmission as claimed in claim 11, in which said separate oscillatable means comprises a pair of axially-aligned sleeves having peripheral cam grooves; and said clutches are means comprises an axially-shiftable shaft extending through said axially-aligned sleeves and provided with means for engaging one of said sleeves in each of its axially-shiftable positions.

14. A transmission as claimed in claim 11, in which a fluid-operated thruster is provided for actuating said reciprocable member.

15. In a transmission for moving an element, a plurality of members mounted on a single shaft and adapted to be shifted between two axial positions; separate oscillatable means for shifting each of said members between their axial positions, said separate means being arranged in aligned relation; a reciprocable member independently movable relatively to said oscillatable means, adapted to cooperate with said oscillatable means to position said members substantially midway between their axial positions; and means responsive to the movement of said element for actuatingsaid reciprocable member substantially instantaneously.

16. In a transmission for operating an apparatus, a plurality of members mounted on parallel spaced shafts and adapted to be shifted between two axial positions; separate oscillatable means for shifting each of said members between their axial positions, said separate oscillatable means being arranged along parallel spaced axes; a reciprocable member independently movable relatively to said oscillatable means, adapted to cooperate with said oscillatable means to position said members substantially midway between their axial positions, and means responsive to the operation of said apparatus for actuating said reciprocable member substantially instantaneously.

17. A transmission for operating an apparatus comprising in combination, a driving shaft; a driven shaft; gearing for transmitting power from said driving shaft to said driven shaft. in-- cluding means for rotating said driven shaft in opposite directions; a clutch for selectively engaging said driven shaft with said oppositely rotatable means; oscillatable means .for shifting said clutch from one axial position through a neutral position to another axial position including a sleeve having a peripheral cam groove; a yoke connected to said clutch and provided with a roller adapted to engage said cam groove; neutralizing means independently movable relatively to said oscillatable means, adapted to cooperate with said oscillatable means for shifting said clutch to its neutral position; and poweroperateci means responsive to the operation of said apparatus for actuating said neutralizing means substantially instantaneously.

18. A transmission for moving an element comprising in combination, a driving shaft; a driven shaft; gearing for transmitting power from said driving shaft to said driven shaft, including means for rotating said driven shaft in opposite directions; a clutch for selectively engaging said driven shaft with said oppositely rotatable means; oscillatable means for shifting said clutch from one axial position through a neutral position to another axial. position; a reciprocable member independently movable relatively to said oscillatable means, adapted to cooperate with said oscillatable means for shifting said clutch to its neutral position; and a fiuid operated thrustor responsive to the movement of said element for actuating said reciprocable member. f

19. In a transmission. for moving an element, a" member adapted to be shifted from one axial position to another axial position; an osciliatable sleeve for shitting said member between said axial positions; afpair oi abutments located on opposite sides of means adapted to cooperate with said sleeve; a reciprocable member having means adapted to cooperate with said abutment's for positioning said sleeve so that said member I is moved to a point'subs'tantiaily midway between said positions; and power-operated means 'res'ponsive'to' the movement of said element for actuating said recipro'cable member substanm ny instantaneously.

20, In a transmission for moving an element,

' 'a member adapted to be shifted from one axial position to another axial position; an osciilatable sleeve having a peripheral cam groove for shifting said member between said axial positions; an arm associated with said member; a roller supportedon said arm and adapted to it within.

said cam groove; a reciprocable member adapted to cooperate withsaid oscillatabie means to position said, member substantially midway between said axial positions; and power-operated means responsive to the movement of said element for actuating. said reciprocable member substantially' instantaneously.

'ing a member adapted to be shifted from one axial positiont'o" another axial position; 'oscillatable means for shifting said member between said axial positions; recip'rocable means for shifting 21. In a transmission for moving an element. a member adapted to be shifted from one axial position to, another axial position: oscillatable means tor shitting said member between said axial positions; a reciprocable member adapted to cooperate with said oscillatable means to position said member substantially midway between said axial positions; and means independent of the movement of both said oscillatable means and said reciprocable member but responsive to the movement of said element for actuating, said reciproeable member.

22. Apparatus for moving an element comprissaid member to a position substantially midway between said axial positions, said reciprocable means being adapted to cooperate'with abutment's located on opposite sides 'of'means that cooperate with said oscillatable means and a fluid-operated thrustor responsive tothe movement 015 said element for'actuating said reciprocable means.

23; In a transmission for moving an element,

a member adapted to be shifted from one axial position to another axial position; oscillatable means for shifting said member between said axial positions; 'reciprocable means independ ently movable "relatively to said oscillatable means, adapted to cooperate with said oscillat able means to position said member substantially midway between said' axial positions; and means responsive to the movement ofsaid elem'ent for actuating said recipr'ocable means substantially instantaneously. m

24. In a transmission for moving an element,

a plurality of members each adapted to be shifted between two axial positions; separate oscillat able means for hifting eachof said members between their axial positions; reciprocable means independently movable relatively to said oscillatable means, adaptedto cooperate with said oscillatable means to position saidmembers substantially midway between their axial, positions; and power-operated means responsive to the movement of said element for actuating said reciprocable member; substantialy instantaneously.

EDWARD P. -BU1'.IIL4ARD,.III. LEROY E. ALVEY.- PAUL H. LANGE. 

